When Epiphone had the headstock that looked like an open book, it was a lot easier for unscrupulous people to convert and sell Epi Les Paul's as Gibson's. It's also why the truss rod cover now uses three screws rather then just two. Metric hardware instead of inch, etc...

I think the headstocks I liked were on the Scroll model:

Similar, but exaggerated. Long curves. Sure, the body looked like what Prince was thinking about before he knew he was thinking about it, but I've always wanted one of these. Found one in a miscellany store once and should've brought it home. They're set apart from most of what Gibson has ever done, and even the odd stuff Epi did back then.